Abstract
OBJECTIVE: Investigating the association between maternal age, anti-Müllerian hormone (AMH) levels, and chromosomal abnormalities in early missed abortion (EMA) embryos, providing evidence for clinical risk stratification and intervention strategies. METHODS: A retrospective cohort study was conducted, including 990 EMA diagnosed patients between June 2020 and December 2024. All patients underwent chorionic villus copy number variant sequencing (CNV-seq) after curettage. The study groups were defined as follows based on two criteria: (1) maternal age at miscarriage: <35, 35-39, and ≥ 40 years; and (2) serum AMH level within one year of enrollment: <1.1, 1.1-4.5, and ≥ 4.5ng/mL. Chromosomal abnormality detection rates and types were compared across groups. RESULTS: Overall, chromosomal abnormalities were detected in 58.59% (580/990) of embryos, predominantly Numerical Chromosomal Abnormalities (88.62%), with trisomies of autosomes being the most common (67.24%), especially trisomy 22 (19.48%) and trisomy 16 (14.14%). Detection rates increased significantly with maternal age (< 35: 54.52%, 386/708; 35-39: 66.99%, 140/209; ≥40: 73.97%, 54/73; p < 0.05). The proportion of autosomal trisomies rose with age, while 45,X, polyploidy, and Copy number variants (CNVs) decreased. Similarly, lower AMH levels were associated with higher chromosomal abnormality rates (≥ 4.5 ng/mL: 50.16%, 158/315; 1.1-4.5 ng/mL: 60.92%, 232/381; <1.1 ng/mL: 69.23%, 90/130; p < 0.05). The rate of autosomal trisomy and double trisomy/polysomy increased with declining AMH (p < 0.05). After stratifying by age to control for its confounding effect, a significant inverse association between AMH level and abnormality rate was observed only in the < 35 years subgroup (134/47.69%; 216/57.45%; 36/70.59%; p < 0.05), but not in the ≥ 35 years subgroup (24/70.59%; 116/68.64%; 54/68.35%; p > 0.05). Logistic regression indicated maternal age (OR = 1.039, 95% CI: 1.019-1.059) and AMH (OR = 0.931, 95% CI: 0.902-0.960) were independent predictors of chromosomal abnormalities. CONCLUSION: Increased maternal age and decreased AMH levels are closely associated with higher risk of chromosomal abnormalities in EMA embryos. As a sensitive indicator of ovarian reserve, AMH reflects oocyte quality and chromosomal stability, particularly in younger women. Combined assessment of maternal age and AMH may improve risk evaluation and inform preventive and intervention strategies for EMA.